Receiver for wireless telegraphy and telephony.



s. EISENSITEIN.

RECEIVER FOR WIRELESS TELEGRAPHY AND TELEPHONY. APPLICATION FILED MAR. 27, 1908.

931,586. Patented Aug. 17, 1909.

WITNESSES ATTORNEYS.

1o metho sIMoN EISENSTEIN, or KIEW, rinssrA.

RECEIVER FOR-WIRELESS TELEGRAPHY AND TELEPHONY.

Specification of Letters Patent.

Patented Aug. 17, 1909.

Application filed March 27, 1908. Serial. No. 423,638.

To all whom it may concern:

Be it known that I, SIMON Ersnns'rnrir, a

5 vented certain new and useful Improve ments in Receivers for lVirelessTelegraphy and Telephony, of which the following is a specification. The resent invention has for its object a of electrical connection for diminishing the damping in the resonant circuit of the receiver by means of which it is also possible tov receive undamped oscillations by means of a' telephone receiver. Poulsen has already suggested (see Elektroteclmische Zeitschfift, Berlin, No. 45, .Nov. 8, 1906', especiall pp. 1042 and-1043 and Figs. 2932) the emp oyment of what is termed a ticker for the purpose of diminishing the damping and for adapting telephone detectors as r e ceivers, the detector only being switched in intermittently when the amplitude in the resonant circuit of the receiver has already attained a high value by resonance, which is relatively readily effected, because, during the increase of the amplitude, the resonant -circuit is given a slight self-dam ing by cutting out the detector. The tic er resents the defect, however, that when the etector is cut out subsidiary vibrations are produced which exert an influence upon the sensitiveness of the receiver. The resent invention aims at the same object ut no make or break place is provided so that the formation .of subsidiar vibrations is entirely avoided,

this object eing attained owing to the fact that the secondary coil of'the receiver transfornler arranged in the resonant circuit of the receiver is brought into the field of the pri- 40 mary coil for a brief moment only, so that it is only during the period in which the secondary coil is not located in the field of the primary coil that the am litude is able to increase with diminished' amping.

' 'The invention is diagrammatically illustrated in the accompanying drawingl Figure 1 illustrates the general arrangement of the apparatus, and Figs. 2 and 3 show'difierent ways of arranging the receiving transformer coils with respect to each other. v v

The antenna 1 is connected with aresonant circuit 2 provided in the usual manner with the receiver transformer or resonator 3, the

capacity 4 and the coupling coil 5. The secwith a capacity 7.

ondary coil 3 of the receiver transformer is connected with the detector 6 and in parallel If the secondary winding of the receiver transformer were not provided, the system would have a very slight damping, which is increased by the interposition of the secondary coil with the detector.

Now as already stated, in accordance with the present invention the secondary coil 3 of the receiver transformer is brought into the field of the primary coil for a brief moment only, so that for the rest of the time with a diminished damping an increase of the amplitude can take place.

By alternating the switching in and cutting out of the secondary'coil in the field of the primary winding, it is possible to receive messages by the telephone. The secondary coil may of course be switched in and out in different ways, for example by the oscillation of the secondary coil or by an eccentric circular-movement in front of the primary coil nected with the detector, is rotatable at a, so

that the coil can turn within the convolutions of the primary member3 on-the axis a. The

secondary member 3 is located in this arrangement, during its rotation only, in the magnetic field of the primary coil when the windings of both coils are parallel with each other, but when the same cross each other, or are arranged at an angle to each other (as shown in Fig.2), no efiect is present, or the same is at least considerably diminished.

In the form shown in Fig. 3, the secondary member 3 is rotatable, by means of a suitable supporting frame, about the point b,and is either moved by an entire circular motion around the point I) or by to and fro oscillation temporarily placed 0' posite the primary member 3, as shown. ft is only when the position shown in the drawing is reached Patent:

1. In apparatus for wireless telegraphy,

the combination, with a resonant circuit and a primary receiving transformer coil in said circuit, of' a secondary i transformer- 'c'oil arranged to .be continuously -moved, with arespect to the primary. coil and connected with a detector.

'2. In apparatus for wireless telegraphy, the combination, with a resonantcircuit and a primary receiving transformer coil in said marycoil, and a detectorc0nnected with said seconda coil.

In testlmony, that I claim the foregoing as my. invention, I have signed my name in presence of two subscribing Witnesses. A

SIMON EISENSTEIN.

Witnesses: V

PETER TRAZEWSKJ H A. LOVIAGUINE- 

